Inorganic‐Alone Solid‐State Electrochromic Device for Application as Visible Near Infrared Region Electronic Curtain

A prototype inorganic material‐based solid‐state electrochromic device (ECD) using an active WO 3 layer has been demonstrated followed by testing its potential application in blocking infrared (IR) radiation. A cost‐effective hydrothermal method has been used for fabricating WO 3 ‐based electrodes. Prior to application, the structural and morphological characterization of the WO 3 has been done using X‐ray diffraction, X‐ray photoelectron spectroscopy, and Raman spectroscopy. A solid‐state ECD has been fabricated in a sandwiched geometry with a supporting gel electrolyte. The solid‐state inorganic ECD displays a color contrast of more than 40% at 600 nm wavelength while toggling between transparent (OFF state) and blue (ON state) colors under a bias of as low as 2.5 V making it a power‐efficient device. The device is capable of maintaining its absorbance switching for longer than 2400 s without altering its absorbance rate. The device is capable of blocking IR radiation with more than 100% in its ON state as compared to its OFF state. A power‐efficient electrochromic performance has been reported from an inorganic‐alone solid state ECD while displaying its potential as an electronic curtain.